Experimental and theoretical studies of the schiff base (Z)-1-(thiophen-2-yl- methyleneamino) propane-2-ol

Abstract

In this study, a quantum chemical model was developed to better account for the properties of a Schiff base, (Z)-1-(thiophen-2-yl-methyleneamino) propane-2-ol, which is derived from thiophene-2-carboxy aldehyde and 1-amino-2-propanol. To predict its molecular structure, the assignment of the vibrational wavelength (for FT-IR) and chemical shift (for (HNMR)-H-1) of (Z)-1-(thiophen-2-yl-methyleneamino) propane-2-ol was performed experimentally and theoretically. All of the theoretical calculations were performed using the Gaussian 09 program package. The theoretically and experimentally obtained results were in good agreement (R-2 >= 0.99). The energies of the highest occupied and lowest unoccupied molecular orbitals were estimated using B3LYP (Becke three-parameter hybrid functional combined with Lee-Yang-Parr correlation functional)/6-311++G (d, p). Optimization of the structure of (Z)-1-(thiophen-2-yl-methyleneamino) propane-2-ol provided information concerning the stable form of the geometry of the molecule, stoichiometry of the complexes, and thermodynamic parameters (e.g., energy and entropy). The results indicate that the Schiff base formed stable complexes with Ni2+. The energy of the complex was much lower than that of the free Schiff base. The charge distribution values of each atom in the Schiff base were in agreement with the Pauling scale for electronegativity and vibrational wavelength.